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4.7.1. 1 Card Sensing Contacts
Inspect contacts for burning. Remove card particles and
lint. One broken contact in a pair causes intermittent read
failures.
4.7.1.2 Sensing Pins
Check that sensing pins operate separately. Pins sticking
together cause reading failures by forcing both pins to enter
the hole at the same time.
4.7.1.3 Pin Bail, Drive Link, and Arm Assembly
Inspect guide stud in the rear frame for wear. Adjust link
and lubricate stud if necessary. Check for rust accumulation
or wear.
4.7.1.4 Card Lever
Remove any accumulation of card dust around the card
lever.
4.7.2 Pin-Sensing Unit Adjustments
Contact pressure, throat gap, and contact gap adjustments
are made with unit removed from base.
4.7.2.1 Contact Pressure
Before installing a new contact molding, pre-form contact
straps (Figure 4-30). A reading board is helpful in forming
contacts evenly.
1. Form contacts as shown in Figure 4-30.
2. Install contacts on pin-sensing unit.
3. Adjust contact pressure by forming the strap near the
molding to require 20 to 30 grams to move the contact
ftom the common bar.
I
Push Molding
Downward
Contoct
Molding
S225-3357-3
FES: SS23-4069
1.7.2.2 Throat Gap
1. Place eject unit in normal operating position on pin-
sensing assembly. Hold together with screws if necessary.
2. Shim throat pkte (bottom of eject unit) to adjust throat
gap for 0.0 12-inch to 0.02 1 -inch clearance (Figure 4-3 1).
I
Check 0.012-inch clearance at closest point and 0.021-
inch clearance at widest point. Replace throat plates
worn beyond these dimensions. The 0.004-inch shim is
part 12 1397, and the 0.0 10-inch shim is part 4990 1.
1
Note: Late production units do not use shims.
4.7.2.3 Contact Gap
1. Insert blank card and let pins rest against it.
2. Remove contact cover and adjust common contact bar
for minimum air gap of 0.020 inch and a maximum air
gap of 0.030 inch (Figure 4-3 1).
4.7.2.4 Pin Bail Arm Eccentric
Normally, it is unnecessary to alter factory adjustment on
pin-bail-arm eccentric stop. If adjustment is necessary,
loosen locking screw and adjust eccentric to stop pin-bail
arm when sensing pins are retracted 0.010 inch to 0.015
inch below surface of separators. Tighten locking screws.
Figure 4-30. Sensing Pin Contact Adjustment
Figure 4-31. Pin Sensing Adjustment
29 FEMM
(11170)
4-17
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